Single molecule detection or quantification by dna nanotechnology in microwells

A method for the detection of a target structure, comprising:

• p1) introduction of a group of host bodies including a host body with a target structure into a microwell array such that exactly one host body is present in at least one microwell;
• p2) introduction of at least two 3D DNA nanostructures into the at least one microwell wherein each of the 3D DNA nanostructures comprises one or more inwardly disposed fluorescence dye molecules;
• a) forming an identification structure in the at least one microwell, comprising:
• (i) the target structure, and
• (ii) the at least two 3D DNA nanostructures, wherein each of the 3D DNA nanostructures is specifically bound to the target structure and wherein the 3D DNA nanostructures are bound to pairwise different regions of the target structure;
• b) detection of the target structure by measuring at least one fluorescence signal,
• wherein the 3D DNA nanostructures and the parameters of fluorescence measurement are selected such that the at least one measured fluorescence signal of the identification structure formed in a) is distinguishable from the fluorescence signal of each of the at least two isolated 3D DNA nanostructures, when these are not bound in the respective identification structure, wherein the identification structure is bound to a first surface, preferably the bottom of the at least one microwell.